This invention relates to an electronically controlled fuel injection system for use in an internal combustion engine having a catalytic converter, and more particularly to a system for enhancing rapid warm-up of the catalyst contained in the catalytic converter during a cold start of an engine.
It is well known in the art to increase the amount of fuel supplied into the combustion chambers of the engine during a cold start in order to provide ready ignition of the engine. As a result, the exhaust gases exhausted from the exhaust ports of the engine contain a great amount of carbon monoxide and hydrocarbons, but only a small amount of oxygen. Thus, if the engine employs a catalytic converter in the exhaust system thereof, the carbon monoxide and the hydrocarbons are introduced into the catalytic converter with a small amount of oxygen. Under these conditions, the catalyst in the converter fails to reach a suitable temperature rapidly due to the shortage of oxygen, and therefore, it takes some time before the catalyst can provide maximum performance.